As one of environment-conscious and highly-efficient refrigerating technique, expectations for a magnetic refrigeration have been increased, leading to increasingly active research and development for magnetic refrigerating techniques designed for a room temperature range.
As one of the magnetic refrigerating techniques, there has been proposed an AMR (Active Magnetic Refrigeration) system in which a lattice entropy, which used to be positioned as an obstructive factor for the magnetic refrigeration in a room temperature range, is positively utilized in order to allow a magnetic material to bear a thermal storage effect for storing cold heat generated by the magnetic refrigerating operation, in addition to the magnetic refrigerating operation caused by the magnetocaloric effect.
The AMR system has been expected to achieve a higher refrigerating efficiency compared to a conventional refrigerating system by a compression cycle using chlorofluorocarbon.
Development of a magnetic refrigerating technique having higher refrigerating efficiency has still been desired from the viewpoint of energy saving.